xref: /openbmc/linux/arch/sparc/kernel/viohs.c (revision b830f94f) 
1 // SPDX-License-Identifier: GPL-2.0
2 /* viohs.c: LDOM Virtual I/O handshake helper layer.
3  *
4  * Copyright (C) 2007 David S. Miller <davem@davemloft.net>
5  */
6 
7 #include <linux/kernel.h>
8 #include <linux/export.h>
9 #include <linux/string.h>
10 #include <linux/delay.h>
11 #include <linux/sched.h>
12 #include <linux/sched/clock.h>
13 #include <linux/slab.h>
14 
15 #include <asm/ldc.h>
16 #include <asm/vio.h>
17 
18 int vio_ldc_send(struct vio_driver_state *vio, void *data, int len)
19 {
20 	int err, limit = 1000;
21 
22 	err = -EINVAL;
23 	while (limit-- > 0) {
24 		err = ldc_write(vio->lp, data, len);
25 		if (!err || (err != -EAGAIN))
26 			break;
27 		udelay(1);
28 	}
29 
30 	return err;
31 }
32 EXPORT_SYMBOL(vio_ldc_send);
33 
34 static int send_ctrl(struct vio_driver_state *vio,
35 		     struct vio_msg_tag *tag, int len)
36 {
37 	tag->sid = vio_send_sid(vio);
38 	return vio_ldc_send(vio, tag, len);
39 }
40 
41 static void init_tag(struct vio_msg_tag *tag, u8 type, u8 stype, u16 stype_env)
42 {
43 	tag->type = type;
44 	tag->stype = stype;
45 	tag->stype_env = stype_env;
46 }
47 
48 static int send_version(struct vio_driver_state *vio, u16 major, u16 minor)
49 {
50 	struct vio_ver_info pkt;
51 
52 	vio->_local_sid = (u32) sched_clock();
53 
54 	memset(&pkt, 0, sizeof(pkt));
55 	init_tag(&pkt.tag, VIO_TYPE_CTRL, VIO_SUBTYPE_INFO, VIO_VER_INFO);
56 	pkt.major = major;
57 	pkt.minor = minor;
58 	pkt.dev_class = vio->dev_class;
59 
60 	viodbg(HS, "SEND VERSION INFO maj[%u] min[%u] devclass[%u]\n",
61 	       major, minor, vio->dev_class);
62 
63 	return send_ctrl(vio, &pkt.tag, sizeof(pkt));
64 }
65 
66 static int start_handshake(struct vio_driver_state *vio)
67 {
68 	int err;
69 
70 	viodbg(HS, "START HANDSHAKE\n");
71 
72 	vio->hs_state = VIO_HS_INVALID;
73 
74 	err = send_version(vio,
75 			   vio->ver_table[0].major,
76 			   vio->ver_table[0].minor);
77 	if (err < 0)
78 		return err;
79 
80 	return 0;
81 }
82 
83 static void flush_rx_dring(struct vio_driver_state *vio)
84 {
85 	struct vio_dring_state *dr;
86 	u64 ident;
87 
88 	BUG_ON(!(vio->dr_state & VIO_DR_STATE_RXREG));
89 
90 	dr = &vio->drings[VIO_DRIVER_RX_RING];
91 	ident = dr->ident;
92 
93 	BUG_ON(!vio->desc_buf);
94 	kfree(vio->desc_buf);
95 	vio->desc_buf = NULL;
96 
97 	memset(dr, 0, sizeof(*dr));
98 	dr->ident = ident;
99 }
100 
101 void vio_link_state_change(struct vio_driver_state *vio, int event)
102 {
103 	if (event == LDC_EVENT_UP) {
104 		vio->hs_state = VIO_HS_INVALID;
105 
106 		switch (vio->dev_class) {
107 		case VDEV_NETWORK:
108 		case VDEV_NETWORK_SWITCH:
109 			vio->dr_state = (VIO_DR_STATE_TXREQ |
110 					 VIO_DR_STATE_RXREQ);
111 			break;
112 
113 		case VDEV_DISK:
114 			vio->dr_state = VIO_DR_STATE_TXREQ;
115 			break;
116 		case VDEV_DISK_SERVER:
117 			vio->dr_state = VIO_DR_STATE_RXREQ;
118 			break;
119 		}
120 		start_handshake(vio);
121 	} else if (event == LDC_EVENT_RESET) {
122 		vio->hs_state = VIO_HS_INVALID;
123 
124 		if (vio->dr_state & VIO_DR_STATE_RXREG)
125 			flush_rx_dring(vio);
126 
127 		vio->dr_state = 0x00;
128 		memset(&vio->ver, 0, sizeof(vio->ver));
129 
130 		ldc_disconnect(vio->lp);
131 	}
132 }
133 EXPORT_SYMBOL(vio_link_state_change);
134 
135 static int handshake_failure(struct vio_driver_state *vio)
136 {
137 	struct vio_dring_state *dr;
138 
139 	/* XXX Put policy here...  Perhaps start a timer to fire
140 	 * XXX in 100 ms, which will bring the link up and retry
141 	 * XXX the handshake.
142 	 */
143 
144 	viodbg(HS, "HANDSHAKE FAILURE\n");
145 
146 	vio->dr_state &= ~(VIO_DR_STATE_TXREG |
147 			   VIO_DR_STATE_RXREG);
148 
149 	dr = &vio->drings[VIO_DRIVER_RX_RING];
150 	memset(dr, 0, sizeof(*dr));
151 
152 	kfree(vio->desc_buf);
153 	vio->desc_buf = NULL;
154 	vio->desc_buf_len = 0;
155 
156 	vio->hs_state = VIO_HS_INVALID;
157 
158 	return -ECONNRESET;
159 }
160 
161 static int process_unknown(struct vio_driver_state *vio, void *arg)
162 {
163 	struct vio_msg_tag *pkt = arg;
164 
165 	viodbg(HS, "UNKNOWN CONTROL [%02x:%02x:%04x:%08x]\n",
166 	       pkt->type, pkt->stype, pkt->stype_env, pkt->sid);
167 
168 	printk(KERN_ERR "vio: ID[%lu] Resetting connection.\n",
169 	       vio->vdev->channel_id);
170 
171 	ldc_disconnect(vio->lp);
172 
173 	return -ECONNRESET;
174 }
175 
176 static int send_dreg(struct vio_driver_state *vio)
177 {
178 	struct vio_dring_state *dr = &vio->drings[VIO_DRIVER_TX_RING];
179 	union {
180 		struct vio_dring_register pkt;
181 		char all[sizeof(struct vio_dring_register) +
182 			 (sizeof(struct ldc_trans_cookie) *
183 			  VIO_MAX_RING_COOKIES)];
184 	} u;
185 	size_t bytes = sizeof(struct vio_dring_register) +
186 		       (sizeof(struct ldc_trans_cookie) *
187 			dr->ncookies);
188 	int i;
189 
190 	if (WARN_ON(bytes > sizeof(u)))
191 		return -EINVAL;
192 
193 	memset(&u, 0, bytes);
194 	init_tag(&u.pkt.tag, VIO_TYPE_CTRL, VIO_SUBTYPE_INFO, VIO_DRING_REG);
195 	u.pkt.dring_ident = 0;
196 	u.pkt.num_descr = dr->num_entries;
197 	u.pkt.descr_size = dr->entry_size;
198 	u.pkt.options = VIO_TX_DRING;
199 	u.pkt.num_cookies = dr->ncookies;
200 
201 	viodbg(HS, "SEND DRING_REG INFO ndesc[%u] dsz[%u] opt[0x%x] "
202 	       "ncookies[%u]\n",
203 	       u.pkt.num_descr, u.pkt.descr_size, u.pkt.options,
204 	       u.pkt.num_cookies);
205 
206 	for (i = 0; i < dr->ncookies; i++) {
207 		u.pkt.cookies[i] = dr->cookies[i];
208 
209 		viodbg(HS, "DRING COOKIE(%d) [%016llx:%016llx]\n",
210 		       i,
211 		       (unsigned long long) u.pkt.cookies[i].cookie_addr,
212 		       (unsigned long long) u.pkt.cookies[i].cookie_size);
213 	}
214 
215 	return send_ctrl(vio, &u.pkt.tag, bytes);
216 }
217 
218 static int send_rdx(struct vio_driver_state *vio)
219 {
220 	struct vio_rdx pkt;
221 
222 	memset(&pkt, 0, sizeof(pkt));
223 
224 	init_tag(&pkt.tag, VIO_TYPE_CTRL, VIO_SUBTYPE_INFO, VIO_RDX);
225 
226 	viodbg(HS, "SEND RDX INFO\n");
227 
228 	return send_ctrl(vio, &pkt.tag, sizeof(pkt));
229 }
230 
231 static int send_attr(struct vio_driver_state *vio)
232 {
233 	if (!vio->ops)
234 		return -EINVAL;
235 
236 	return vio->ops->send_attr(vio);
237 }
238 
239 static struct vio_version *find_by_major(struct vio_driver_state *vio,
240 					 u16 major)
241 {
242 	struct vio_version *ret = NULL;
243 	int i;
244 
245 	for (i = 0; i < vio->ver_table_entries; i++) {
246 		struct vio_version *v = &vio->ver_table[i];
247 		if (v->major <= major) {
248 			ret = v;
249 			break;
250 		}
251 	}
252 	return ret;
253 }
254 
255 static int process_ver_info(struct vio_driver_state *vio,
256 			    struct vio_ver_info *pkt)
257 {
258 	struct vio_version *vap;
259 	int err;
260 
261 	viodbg(HS, "GOT VERSION INFO maj[%u] min[%u] devclass[%u]\n",
262 	       pkt->major, pkt->minor, pkt->dev_class);
263 
264 	if (vio->hs_state != VIO_HS_INVALID) {
265 		/* XXX Perhaps invoke start_handshake? XXX */
266 		memset(&vio->ver, 0, sizeof(vio->ver));
267 		vio->hs_state = VIO_HS_INVALID;
268 	}
269 
270 	vap = find_by_major(vio, pkt->major);
271 
272 	vio->_peer_sid = pkt->tag.sid;
273 
274 	if (!vap) {
275 		pkt->tag.stype = VIO_SUBTYPE_NACK;
276 		pkt->major = 0;
277 		pkt->minor = 0;
278 		viodbg(HS, "SEND VERSION NACK maj[0] min[0]\n");
279 		err = send_ctrl(vio, &pkt->tag, sizeof(*pkt));
280 	} else if (vap->major != pkt->major) {
281 		pkt->tag.stype = VIO_SUBTYPE_NACK;
282 		pkt->major = vap->major;
283 		pkt->minor = vap->minor;
284 		viodbg(HS, "SEND VERSION NACK maj[%u] min[%u]\n",
285 		       pkt->major, pkt->minor);
286 		err = send_ctrl(vio, &pkt->tag, sizeof(*pkt));
287 	} else {
288 		struct vio_version ver = {
289 			.major = pkt->major,
290 			.minor = pkt->minor,
291 		};
292 		if (ver.minor > vap->minor)
293 			ver.minor = vap->minor;
294 		pkt->minor = ver.minor;
295 		pkt->tag.stype = VIO_SUBTYPE_ACK;
296 		pkt->dev_class = vio->dev_class;
297 		viodbg(HS, "SEND VERSION ACK maj[%u] min[%u]\n",
298 		       pkt->major, pkt->minor);
299 		err = send_ctrl(vio, &pkt->tag, sizeof(*pkt));
300 		if (err > 0) {
301 			vio->ver = ver;
302 			vio->hs_state = VIO_HS_GOTVERS;
303 		}
304 	}
305 	if (err < 0)
306 		return handshake_failure(vio);
307 
308 	return 0;
309 }
310 
311 static int process_ver_ack(struct vio_driver_state *vio,
312 			   struct vio_ver_info *pkt)
313 {
314 	viodbg(HS, "GOT VERSION ACK maj[%u] min[%u] devclass[%u]\n",
315 	       pkt->major, pkt->minor, pkt->dev_class);
316 
317 	if (vio->hs_state & VIO_HS_GOTVERS) {
318 		if (vio->ver.major != pkt->major ||
319 		    vio->ver.minor != pkt->minor) {
320 			pkt->tag.stype = VIO_SUBTYPE_NACK;
321 			(void) send_ctrl(vio, &pkt->tag, sizeof(*pkt));
322 			return handshake_failure(vio);
323 		}
324 	} else {
325 		vio->ver.major = pkt->major;
326 		vio->ver.minor = pkt->minor;
327 		vio->hs_state = VIO_HS_GOTVERS;
328 	}
329 
330 	switch (vio->dev_class) {
331 	case VDEV_NETWORK:
332 	case VDEV_DISK:
333 		if (send_attr(vio) < 0)
334 			return handshake_failure(vio);
335 		break;
336 
337 	default:
338 		break;
339 	}
340 
341 	return 0;
342 }
343 
344 static int process_ver_nack(struct vio_driver_state *vio,
345 			    struct vio_ver_info *pkt)
346 {
347 	struct vio_version *nver;
348 
349 	viodbg(HS, "GOT VERSION NACK maj[%u] min[%u] devclass[%u]\n",
350 	       pkt->major, pkt->minor, pkt->dev_class);
351 
352 	if (pkt->major == 0 && pkt->minor == 0)
353 		return handshake_failure(vio);
354 	nver = find_by_major(vio, pkt->major);
355 	if (!nver)
356 		return handshake_failure(vio);
357 
358 	if (send_version(vio, nver->major, nver->minor) < 0)
359 		return handshake_failure(vio);
360 
361 	return 0;
362 }
363 
364 static int process_ver(struct vio_driver_state *vio, struct vio_ver_info *pkt)
365 {
366 	switch (pkt->tag.stype) {
367 	case VIO_SUBTYPE_INFO:
368 		return process_ver_info(vio, pkt);
369 
370 	case VIO_SUBTYPE_ACK:
371 		return process_ver_ack(vio, pkt);
372 
373 	case VIO_SUBTYPE_NACK:
374 		return process_ver_nack(vio, pkt);
375 
376 	default:
377 		return handshake_failure(vio);
378 	}
379 }
380 
381 static int process_attr(struct vio_driver_state *vio, void *pkt)
382 {
383 	int err;
384 
385 	if (!(vio->hs_state & VIO_HS_GOTVERS))
386 		return handshake_failure(vio);
387 
388 	if (!vio->ops)
389 		return 0;
390 
391 	err = vio->ops->handle_attr(vio, pkt);
392 	if (err < 0) {
393 		return handshake_failure(vio);
394 	} else {
395 		vio->hs_state |= VIO_HS_GOT_ATTR;
396 
397 		if ((vio->dr_state & VIO_DR_STATE_TXREQ) &&
398 		    !(vio->hs_state & VIO_HS_SENT_DREG)) {
399 			if (send_dreg(vio) < 0)
400 				return handshake_failure(vio);
401 
402 			vio->hs_state |= VIO_HS_SENT_DREG;
403 		}
404 	}
405 
406 	return 0;
407 }
408 
409 static int all_drings_registered(struct vio_driver_state *vio)
410 {
411 	int need_rx, need_tx;
412 
413 	need_rx = (vio->dr_state & VIO_DR_STATE_RXREQ);
414 	need_tx = (vio->dr_state & VIO_DR_STATE_TXREQ);
415 
416 	if (need_rx &&
417 	    !(vio->dr_state & VIO_DR_STATE_RXREG))
418 		return 0;
419 
420 	if (need_tx &&
421 	    !(vio->dr_state & VIO_DR_STATE_TXREG))
422 		return 0;
423 
424 	return 1;
425 }
426 
427 static int process_dreg_info(struct vio_driver_state *vio,
428 			     struct vio_dring_register *pkt)
429 {
430 	struct vio_dring_state *dr;
431 	int i, len;
432 
433 	viodbg(HS, "GOT DRING_REG INFO ident[%llx] "
434 	       "ndesc[%u] dsz[%u] opt[0x%x] ncookies[%u]\n",
435 	       (unsigned long long) pkt->dring_ident,
436 	       pkt->num_descr, pkt->descr_size, pkt->options,
437 	       pkt->num_cookies);
438 
439 	if (!(vio->dr_state & VIO_DR_STATE_RXREQ))
440 		goto send_nack;
441 
442 	if (vio->dr_state & VIO_DR_STATE_RXREG)
443 		goto send_nack;
444 
445 	/* v1.6 and higher, ACK with desired, supported mode, or NACK */
446 	if (vio_version_after_eq(vio, 1, 6)) {
447 		if (!(pkt->options & VIO_TX_DRING))
448 			goto send_nack;
449 		pkt->options = VIO_TX_DRING;
450 	}
451 
452 	BUG_ON(vio->desc_buf);
453 
454 	vio->desc_buf = kzalloc(pkt->descr_size, GFP_ATOMIC);
455 	if (!vio->desc_buf)
456 		goto send_nack;
457 
458 	vio->desc_buf_len = pkt->descr_size;
459 
460 	dr = &vio->drings[VIO_DRIVER_RX_RING];
461 
462 	dr->num_entries = pkt->num_descr;
463 	dr->entry_size = pkt->descr_size;
464 	dr->ncookies = pkt->num_cookies;
465 	for (i = 0; i < dr->ncookies; i++) {
466 		dr->cookies[i] = pkt->cookies[i];
467 
468 		viodbg(HS, "DRING COOKIE(%d) [%016llx:%016llx]\n",
469 		       i,
470 		       (unsigned long long)
471 		       pkt->cookies[i].cookie_addr,
472 		       (unsigned long long)
473 		       pkt->cookies[i].cookie_size);
474 	}
475 
476 	pkt->tag.stype = VIO_SUBTYPE_ACK;
477 	pkt->dring_ident = ++dr->ident;
478 
479 	viodbg(HS, "SEND DRING_REG ACK ident[%llx] "
480 	       "ndesc[%u] dsz[%u] opt[0x%x] ncookies[%u]\n",
481 	       (unsigned long long) pkt->dring_ident,
482 	       pkt->num_descr, pkt->descr_size, pkt->options,
483 	       pkt->num_cookies);
484 
485 	len = (sizeof(*pkt) +
486 	       (dr->ncookies * sizeof(struct ldc_trans_cookie)));
487 	if (send_ctrl(vio, &pkt->tag, len) < 0)
488 		goto send_nack;
489 
490 	vio->dr_state |= VIO_DR_STATE_RXREG;
491 
492 	return 0;
493 
494 send_nack:
495 	pkt->tag.stype = VIO_SUBTYPE_NACK;
496 	viodbg(HS, "SEND DRING_REG NACK\n");
497 	(void) send_ctrl(vio, &pkt->tag, sizeof(*pkt));
498 
499 	return handshake_failure(vio);
500 }
501 
502 static int process_dreg_ack(struct vio_driver_state *vio,
503 			    struct vio_dring_register *pkt)
504 {
505 	struct vio_dring_state *dr;
506 
507 	viodbg(HS, "GOT DRING_REG ACK ident[%llx] "
508 	       "ndesc[%u] dsz[%u] opt[0x%x] ncookies[%u]\n",
509 	       (unsigned long long) pkt->dring_ident,
510 	       pkt->num_descr, pkt->descr_size, pkt->options,
511 	       pkt->num_cookies);
512 
513 	dr = &vio->drings[VIO_DRIVER_TX_RING];
514 
515 	if (!(vio->dr_state & VIO_DR_STATE_TXREQ))
516 		return handshake_failure(vio);
517 
518 	dr->ident = pkt->dring_ident;
519 	vio->dr_state |= VIO_DR_STATE_TXREG;
520 
521 	if (all_drings_registered(vio)) {
522 		if (send_rdx(vio) < 0)
523 			return handshake_failure(vio);
524 		vio->hs_state = VIO_HS_SENT_RDX;
525 	}
526 	return 0;
527 }
528 
529 static int process_dreg_nack(struct vio_driver_state *vio,
530 			     struct vio_dring_register *pkt)
531 {
532 	viodbg(HS, "GOT DRING_REG NACK ident[%llx] "
533 	       "ndesc[%u] dsz[%u] opt[0x%x] ncookies[%u]\n",
534 	       (unsigned long long) pkt->dring_ident,
535 	       pkt->num_descr, pkt->descr_size, pkt->options,
536 	       pkt->num_cookies);
537 
538 	return handshake_failure(vio);
539 }
540 
541 static int process_dreg(struct vio_driver_state *vio,
542 			struct vio_dring_register *pkt)
543 {
544 	if (!(vio->hs_state & VIO_HS_GOTVERS))
545 		return handshake_failure(vio);
546 
547 	switch (pkt->tag.stype) {
548 	case VIO_SUBTYPE_INFO:
549 		return process_dreg_info(vio, pkt);
550 
551 	case VIO_SUBTYPE_ACK:
552 		return process_dreg_ack(vio, pkt);
553 
554 	case VIO_SUBTYPE_NACK:
555 		return process_dreg_nack(vio, pkt);
556 
557 	default:
558 		return handshake_failure(vio);
559 	}
560 }
561 
562 static int process_dunreg(struct vio_driver_state *vio,
563 			  struct vio_dring_unregister *pkt)
564 {
565 	struct vio_dring_state *dr = &vio->drings[VIO_DRIVER_RX_RING];
566 
567 	viodbg(HS, "GOT DRING_UNREG\n");
568 
569 	if (pkt->dring_ident != dr->ident)
570 		return 0;
571 
572 	vio->dr_state &= ~VIO_DR_STATE_RXREG;
573 
574 	memset(dr, 0, sizeof(*dr));
575 
576 	kfree(vio->desc_buf);
577 	vio->desc_buf = NULL;
578 	vio->desc_buf_len = 0;
579 
580 	return 0;
581 }
582 
583 static int process_rdx_info(struct vio_driver_state *vio, struct vio_rdx *pkt)
584 {
585 	viodbg(HS, "GOT RDX INFO\n");
586 
587 	pkt->tag.stype = VIO_SUBTYPE_ACK;
588 	viodbg(HS, "SEND RDX ACK\n");
589 	if (send_ctrl(vio, &pkt->tag, sizeof(*pkt)) < 0)
590 		return handshake_failure(vio);
591 
592 	vio->hs_state |= VIO_HS_SENT_RDX_ACK;
593 	return 0;
594 }
595 
596 static int process_rdx_ack(struct vio_driver_state *vio, struct vio_rdx *pkt)
597 {
598 	viodbg(HS, "GOT RDX ACK\n");
599 
600 	if (!(vio->hs_state & VIO_HS_SENT_RDX))
601 		return handshake_failure(vio);
602 
603 	vio->hs_state |= VIO_HS_GOT_RDX_ACK;
604 	return 0;
605 }
606 
607 static int process_rdx_nack(struct vio_driver_state *vio, struct vio_rdx *pkt)
608 {
609 	viodbg(HS, "GOT RDX NACK\n");
610 
611 	return handshake_failure(vio);
612 }
613 
614 static int process_rdx(struct vio_driver_state *vio, struct vio_rdx *pkt)
615 {
616 	if (!all_drings_registered(vio))
617 		handshake_failure(vio);
618 
619 	switch (pkt->tag.stype) {
620 	case VIO_SUBTYPE_INFO:
621 		return process_rdx_info(vio, pkt);
622 
623 	case VIO_SUBTYPE_ACK:
624 		return process_rdx_ack(vio, pkt);
625 
626 	case VIO_SUBTYPE_NACK:
627 		return process_rdx_nack(vio, pkt);
628 
629 	default:
630 		return handshake_failure(vio);
631 	}
632 }
633 
634 int vio_control_pkt_engine(struct vio_driver_state *vio, void *pkt)
635 {
636 	struct vio_msg_tag *tag = pkt;
637 	u8 prev_state = vio->hs_state;
638 	int err;
639 
640 	switch (tag->stype_env) {
641 	case VIO_VER_INFO:
642 		err = process_ver(vio, pkt);
643 		break;
644 
645 	case VIO_ATTR_INFO:
646 		err = process_attr(vio, pkt);
647 		break;
648 
649 	case VIO_DRING_REG:
650 		err = process_dreg(vio, pkt);
651 		break;
652 
653 	case VIO_DRING_UNREG:
654 		err = process_dunreg(vio, pkt);
655 		break;
656 
657 	case VIO_RDX:
658 		err = process_rdx(vio, pkt);
659 		break;
660 
661 	default:
662 		err = process_unknown(vio, pkt);
663 		break;
664 	}
665 
666 	if (!err &&
667 	    vio->hs_state != prev_state &&
668 	    (vio->hs_state & VIO_HS_COMPLETE)) {
669 		if (vio->ops)
670 			vio->ops->handshake_complete(vio);
671 	}
672 
673 	return err;
674 }
675 EXPORT_SYMBOL(vio_control_pkt_engine);
676 
677 void vio_conn_reset(struct vio_driver_state *vio)
678 {
679 }
680 EXPORT_SYMBOL(vio_conn_reset);
681 
682 /* The issue is that the Solaris virtual disk server just mirrors the
683  * SID values it gets from the client peer.  So we work around that
684  * here in vio_{validate,send}_sid() so that the drivers don't need
685  * to be aware of this crap.
686  */
687 int vio_validate_sid(struct vio_driver_state *vio, struct vio_msg_tag *tp)
688 {
689 	u32 sid;
690 
691 	/* Always let VERSION+INFO packets through unchecked, they
692 	 * define the new SID.
693 	 */
694 	if (tp->type == VIO_TYPE_CTRL &&
695 	    tp->stype == VIO_SUBTYPE_INFO &&
696 	    tp->stype_env == VIO_VER_INFO)
697 		return 0;
698 
699 	/* Ok, now figure out which SID to use.  */
700 	switch (vio->dev_class) {
701 	case VDEV_NETWORK:
702 	case VDEV_NETWORK_SWITCH:
703 	case VDEV_DISK_SERVER:
704 	default:
705 		sid = vio->_peer_sid;
706 		break;
707 
708 	case VDEV_DISK:
709 		sid = vio->_local_sid;
710 		break;
711 	}
712 
713 	if (sid == tp->sid)
714 		return 0;
715 	viodbg(DATA, "BAD SID tag->sid[%08x] peer_sid[%08x] local_sid[%08x]\n",
716 	       tp->sid, vio->_peer_sid, vio->_local_sid);
717 	return -EINVAL;
718 }
719 EXPORT_SYMBOL(vio_validate_sid);
720 
721 u32 vio_send_sid(struct vio_driver_state *vio)
722 {
723 	switch (vio->dev_class) {
724 	case VDEV_NETWORK:
725 	case VDEV_NETWORK_SWITCH:
726 	case VDEV_DISK:
727 	default:
728 		return vio->_local_sid;
729 
730 	case VDEV_DISK_SERVER:
731 		return vio->_peer_sid;
732 	}
733 }
734 EXPORT_SYMBOL(vio_send_sid);
735 
736 int vio_ldc_alloc(struct vio_driver_state *vio,
737 			 struct ldc_channel_config *base_cfg,
738 			 void *event_arg)
739 {
740 	struct ldc_channel_config cfg = *base_cfg;
741 	struct ldc_channel *lp;
742 
743 	cfg.tx_irq = vio->vdev->tx_irq;
744 	cfg.rx_irq = vio->vdev->rx_irq;
745 
746 	lp = ldc_alloc(vio->vdev->channel_id, &cfg, event_arg, vio->name);
747 	if (IS_ERR(lp))
748 		return PTR_ERR(lp);
749 
750 	vio->lp = lp;
751 
752 	return 0;
753 }
754 EXPORT_SYMBOL(vio_ldc_alloc);
755 
756 void vio_ldc_free(struct vio_driver_state *vio)
757 {
758 	ldc_free(vio->lp);
759 	vio->lp = NULL;
760 
761 	kfree(vio->desc_buf);
762 	vio->desc_buf = NULL;
763 	vio->desc_buf_len = 0;
764 }
765 EXPORT_SYMBOL(vio_ldc_free);
766 
767 void vio_port_up(struct vio_driver_state *vio)
768 {
769 	unsigned long flags;
770 	int err, state;
771 
772 	spin_lock_irqsave(&vio->lock, flags);
773 
774 	state = ldc_state(vio->lp);
775 
776 	err = 0;
777 	if (state == LDC_STATE_INIT) {
778 		err = ldc_bind(vio->lp);
779 		if (err)
780 			printk(KERN_WARNING "%s: Port %lu bind failed, "
781 			       "err=%d\n",
782 			       vio->name, vio->vdev->channel_id, err);
783 	}
784 
785 	if (!err) {
786 		if (ldc_mode(vio->lp) == LDC_MODE_RAW)
787 			ldc_set_state(vio->lp, LDC_STATE_CONNECTED);
788 		else
789 			err = ldc_connect(vio->lp);
790 
791 		if (err)
792 			printk(KERN_WARNING "%s: Port %lu connect failed, "
793 			       "err=%d\n",
794 			       vio->name, vio->vdev->channel_id, err);
795 	}
796 	if (err) {
797 		unsigned long expires = jiffies + HZ;
798 
799 		expires = round_jiffies(expires);
800 		mod_timer(&vio->timer, expires);
801 	}
802 
803 	spin_unlock_irqrestore(&vio->lock, flags);
804 }
805 EXPORT_SYMBOL(vio_port_up);
806 
807 static void vio_port_timer(struct timer_list *t)
808 {
809 	struct vio_driver_state *vio = from_timer(vio, t, timer);
810 
811 	vio_port_up(vio);
812 }
813 
814 int vio_driver_init(struct vio_driver_state *vio, struct vio_dev *vdev,
815 		    u8 dev_class, struct vio_version *ver_table,
816 		    int ver_table_size, struct vio_driver_ops *ops,
817 		    char *name)
818 {
819 	switch (dev_class) {
820 	case VDEV_NETWORK:
821 	case VDEV_NETWORK_SWITCH:
822 	case VDEV_DISK:
823 	case VDEV_DISK_SERVER:
824 	case VDEV_CONSOLE_CON:
825 		break;
826 
827 	default:
828 		return -EINVAL;
829 	}
830 
831 	if (dev_class == VDEV_NETWORK ||
832 	    dev_class == VDEV_NETWORK_SWITCH ||
833 	    dev_class == VDEV_DISK ||
834 	    dev_class == VDEV_DISK_SERVER) {
835 		if (!ops || !ops->send_attr || !ops->handle_attr ||
836 		    !ops->handshake_complete)
837 			return -EINVAL;
838 	}
839 
840 	if (!ver_table || ver_table_size < 0)
841 		return -EINVAL;
842 
843 	if (!name)
844 		return -EINVAL;
845 
846 	spin_lock_init(&vio->lock);
847 
848 	vio->name = name;
849 
850 	vio->dev_class = dev_class;
851 	vio->vdev = vdev;
852 
853 	vio->ver_table = ver_table;
854 	vio->ver_table_entries = ver_table_size;
855 
856 	vio->ops = ops;
857 
858 	timer_setup(&vio->timer, vio_port_timer, 0);
859 
860 	return 0;
861 }
862 EXPORT_SYMBOL(vio_driver_init);
863